Porpoise Type Ride

[jstorey1956]

I have a 2016 Rockwood Signature Travel Trailer, pull weight approx. 8300 lb. I am pulling it with a 2015 Silverado High Country, 6.2L Engine, it is rated to pull 10,000lbs.

While the truck pulls the camper without any issue, when going across those spots on the road that is a dip or rise, the up and down motion is more severe than it should. The truck is not bottoming out, but my stomach is...

Any one have suggestions for firming up the backend while pulling the camper?

[hohenwald48]

Additionally, other than Louisiana, Birmingham has the worst interstate highways in the United States. Nothing will ride well going thru there. I avoid it at all costs and I live in Nashville where all roads south lead to Birmingham. I still manage to go around if I have any choice at all.

Until you tow in some other locations I'd be highly suspect of the roadway.

[colliehauler]

Do you have a weight distribution hitch?

[dodge_guy]

You need to know the real loaded weight of the camper, then you need to have 12.5% of that number for the tongue weight. If the tongue weight is too low and you have a hitch rated for more than the tongue weight you'll get that porpoising sensation you feel. Also this is just another reason to have a WD hitch that is matched to the actual loaded tongue weight.

[ktmrfs]

my experience with two gm 2500's is that the stock shocks are not valved for heavy towing. A set of bilsteins will HELP. Note I said, help. not eliminate the problem. part of the problem is basic physics in the coupling between the trailer and tow vehicle, especially on frost heaves or bad concrete roads.

To futher reduce the problem an Air Safe Air hitch will make a huge improvement. But it comes with a price (a) $$$, not inexpensive, but does what it claims, and (b) it's heavy hitch, around 100lbs for the Class VI which I have.

It does work well with a WD hitch, no issue there.

[WNYBob]

I had the same issue when I had a TC. (See my profile)

Changed shocks and E tires, which made the most difference.

[handye9]

donn0128 wrote:
Let the scales become your new best friend. Stop guessing and get accurate weights.

In addition to this.

Verify all of the various ratings (GVWR, Payload (AKA occupant / cargo capacity), GCVWR) on your particular truck. Keep in mind, manufacturers max tow ratings are an "UP TO XXXX lbs when properly equipped" number. Those numbers do not include aftermarket accessories (undercoating, bed liners, bed covers, step bars, tool boxes, etc), passengers, or cargo. Each and every truck will vary, depending on how it is equipped and how it is loaded. Adding weight from accessories, passengers, and cargo, reduces the truck's true towing capacity.

If the manufacturer says the truck can tow up to 10,000 lbs, and your accessories, passengers, and cargo weigh 1000 lbs, your true max tow capacity is 9,000 lbs, and your available payload is reduced by 1000 lbs.

When you go for your actual weights, have the truck and trailer loaded (including water, if that is how you travel) as if you're going camping. You may find you are much closer to your max weight, than you think you are.

If you are still within your rating numbers, a few things that you can do to help with the ride are adjusting the WD hitch, adding Timbren SES, airbags, or helper springs, adding tire pressure (do not exceed max pressure printed on tire sidewall), or changing tires to something rated for a heavier load.

[silverfz]

Let me share my experience. I tow a 7k camper with a Tundra CrewMax. We usually carry 100-200 lbs of bikes in the back max. so I am close to PayLoad.

My tundra used to do the same thing when I moved form a popup to TT.
The rear tokico`s where shot to death at 90k. Upgraded to Blistein 4600 HD rear shock. This fixed the roller coaster ride .

This winter I added some airbag I plan to run on adjust the hitch height back to where I set it up after adding people/stuff.
Again, mine used to be like riding a rollercoaster when I hit a transitions on the highway. All that is gone just with the rear shock swap.

[Thom02099]

jstorey1956 wrote:
I'm in the Birmingham AL area, and it is concrete sections where the bounce occurs.
Its an interesting problem for me. And the ideas are great.

If it's on a concrete roadway, and not on an asphalt roadway, it's likely a poorly constructed concrete roadway. There are many concrete road surfaces out here in Colorado that do the same; other concrete roadways, not so much. And not at all on asphalt.

That said, the suggestions above about getting proper weights is still great advice.

[jstorey1956]

I'm in the Birmingham AL area, and it is concrete sections where the bounce occurs.
Its an interesting problem for me. And the ideas are great.

[eDUBz]

When i was towing with my half ton tahoe i called up Doetsch Tech and had them Make me a beefier shock for towing, worked really well but the downside is the ride is a lil more stiff for everyday driving but we already got use to it.

[We_Cant_Wait]

Is the highway concrete in the area you're experiencing this? There is one section of I-90 thru Buffalo NY that is concrete and the sections each of such a length between the rubber dividers that when we had our 2 different trailers there was nothing that I could due to stop this issue. The truck and trailer would set up a rhythmic bounce due to the highway not my set-up.

[gmw_photos]

I would weigh it with three passes over the CAT scale to get all the relevant weights. Load the trailer to get approx 13% tongue weight.

Adjust the WD hitch to achieve close to 50% FALR and see how it handles then. If still experiencing unacceptable ride, I would then adjust up the WD to achieve a "slightly" higher FALR ( maybe increasing it to 60% ), then re-evaluate. At no point in this process of experimenting would I go over 100% FALR.

This is a big trailer in relation to the truck, so it likely is going to take some fine tuning to get it to it's sweet spot.

Good quality shocks on the rear of the truck may help also. I like Bilstein 5100, but I suspect there are others that work well also.

[jstorey1956]

Good ideas, thanks for the feed back

[goducks10]

8300lbs vs 5500lbs? Looks like 8300lbs is winning.

[Big_Love]

X2
Make sure that your WDH is adjusted properly (by getting weights) and consider air bags to help assist your rear suspension.